The invention relates to data transfer, such as Local Interconnect Network (LIN) data communication, via a power supply line, e.g. an automotive power supply backbone. For example, LIN may be advantageously combined with a Power Line Communication (PLC) modem in order to avoid the need for additional signaling wires, e.g. a PLC approach may enable existing power cables to provide the physical layer for standard automotive communication protocols, or may act as a low-cost backup physical layer to critical communication lines.
While data transfer over household power distribution lines is also known in the art, higher requirements on the robustness, e.g. in terms of Quality of Service, exist in automotive environments than in domestic use. For example, if an end user turns on a power tool or other heavy inductive loads connected to the power network, e.g. in an adjacent room, it may not be uncommon for a powerline local area network (LAN) to temporarily loose connection or at least drop some data packages. While this may be considered as a normal result of the spike in power use, or at least not as unexpected under these conditions, in a vehicle, e.g. a car, a data connection failure, even temporarily, could have severe consequences. For example, vehicle safety could be compromised. Furthermore, even if an automotive data communication error is not directly a risk to vehicle safety, from a user point of view it would be seen as very unpleasant, if, for example, a window lifter would not be operational in case the wipers are active.
Furthermore, an automotive powerline net may typically be a low voltage direct current net, e.g. a 12 V DC net, while domestic power distribution may typically relate to higher voltages and alternating current, e.g. 230V AC as common in Europe. The automotive power supply is routed in parallel to many other signal lines, e.g. real-time buses such as a CAN bus, a LIN bus, an Ethernet network and/or others. The automotive harness in its complexity may thus relate to a more dense and noisy environment than a domestic power grid. This implies also that an automotive supply can have huge fluctuations in its transfer function, e.g. in its frequency response.
International patent application WO 2009/036834 discloses a related method for data communication in a vehicle which takes place exclusively by means of a supply line structure. A transceiver transmits bits via the supply line structure, and all higher tasks defined in the open systems interconnection (OSI) reference model of the International Organization for Standardization are performed by a microprocessor or microcontroller. For example, LIN or controller area network (CAN) data may be encapsulated via the OSI layer model and transmitted over the power line.